(1) Field of the Invention
The present invention relates to a method for replacing outer bases for vane assemblies with mechanically retained vanes and a turbine engine component resulting from the method.
(2) Prior Art
As shown in FIGS. 1 and 2, an outlet guide vane assembly 10 used in gas turbine engines has an inner composite base 12 and an outer composite base 14 that positions composite vane airfoils 16 during service. The assembly is bolted to the inner diameter of a cylindrical metal case (not shown) by three bolts extending thru the case and the outer base. The inner base is bonded to the vane airfoil and is inseparable without destroying the inner base. The outer base to vane end interface is a bonded assembly which incorporates mechanical retention where the vane end 18 is flared and the vane cavity 20 in the outer base 14 pinches. The vane airfoil is both bonded to and mechanically retained by the outer base. The result is that the vane 22 cannot fall through the base 14 without material rupture of the base and/or vane. The metallic case (not shown) prevents movement of the flared vane end 18 in the outboard direction.
The mechanical retention feature prevents installation of replacement outer base detail without complete removal and replacement of the inner base 12 because neither the inner base, nor the flared vane end 18 can fit through the pinched vane cavity 20.
The outer base is the feature most prone to impact and flexural damage as a result of fan blade centrifuged objects and fan case flexure. Accordingly, there is a need for an economic method for replacing damaged outer bases.